System and method for making incisions for scleral eye implants

ABSTRACT

A system and method is disclosed for making incisions in the sclera of an eye to form a scleral pocket to receive a scleral prosthesis. The system and method comprises a surgical tool comprising a surgical blade for making incisions in the sclera of an eye. When a surgeon places the surgical blade on the sclera of the eye a pressure sensor in the surgical tool determines whether there is sufficient pressure between the surgical tool and the sclera of the eye for the surgical tool to operate properly. The surgeon activates the surgical tool to cause the surgical blade to advance through the sclera to form an incision having dimensions to receive a scleral prosthesis. When the incision is complete the surgical blade is rotated back out of the incision. The incision has the exact dimensions to receive a scleral prosthesis.

PRIORITY CLAIM TO PROVISIONAL PATENT APPLICATION

This patent application claims priority to U.S. Provisional PatentApplication Ser. No. 60/271,028 filed on Feb. 23, 2001.

CROSS-REFERENCE TO RELATED PATENT DOCUMENTS

The present disclosure is related to the inventions disclosed in thefollowing United States patent applications and issued United Statespatents:

-   -   (1) U.S. Pat. No. 6,299,640 entitled “SCLERAL PROSTHESIS FOR        TREATMENT OF PRESBYOPIA AND OTHER EYE DISORDERS” issued on Oct.        9, 2001;    -   (2) U.S. Pat. No. 6,197,056 entitled “SEGMENTED SCLERAL BAND FOR        TREATMENT OF PRESBYOPIAAND OTHER EYE DISORDERS” issued on Mar.        6, 2001;    -   (3) U.S. Pat. No. 6,280,468 entitled “SCLERAL PROSTHESIS FOR        TREATMENT OF PRESBYOPIAAND OTHER EYE DISORDERS” issued Aug. 28,        2001;    -   (4) U.S. Pat. No. 5, 465,737 entitled “TREATMENT OF PRESBYOPIA        AND OTHER EYE DISORDERS” issued on Nov. 14, 1995;    -   (5) U.S. Pat. No. 5,489,299 entitled “TREATMENT OF PRESBYOPIA        AND OTHER EYE DISORDERS” issued on Feb. 6, 1996;    -   (6) U.S. Pat. No. 5,503,165 entitled “TREATMENT OF PRESBYOPIA        AND OTHER EYE DISORDERS” issued on Apr. 2, 1996;    -   (7) U.S. Pat. No. 5,529,076 entitled “TREATMENT OF PRESBYOPIA        AND OTHER EYE DISORDERS” issued on Jun. 25, 1996;    -   (8) U.S. Pat. No. 5,354,331 entitled “TREATMENT OF PRESBYOPIA        AND OTHER EYE DISORDERS” issued on Oct. 11, 1994; and    -   (9) U.S. Pat. No. 5,722,952 entitled “TREAMENT OF PRESBYOPIA        AOTHER EYE DISORDERS” issued on Mar. 3, 1998; which are commonly        owned by the assignee of the present invention. The disclosures        of these related United States patent applications and issued        United States patents (collectively referred to hereafter as the        “Presbyopia and Related Eye Disorder Patent Documents”) are        incorporated herein by reference for all purposes as if fully        set forth herein.

FIELD OF THE INVENTION

The present invention relates generally to the treatment of presbyopia,hyperopia, primary open angle glaucoma, ocular hypertension and othersimilar eye disorders. The present invention comprises a system andmethod for making incisions within the sclera of an eye for the eye toreceive a scleral prosthesis. Scleral prostheses are capable ofincreasing the amplitude of accommodation of the eye by increasing theeffective working range of the ciliary muscle of the eye.

BACKGROUND OF THE INVENTION

In order for the human eye to have clear vision of objects at differentdistances, the effective focal length of the eye must be adjusted tokeep the image of the object focused as sharply as possible on theretina. This change in effective focal length is known as accommodationand is accomplished in the eye by varying the shape of the crystallinelens. Generally, in the unaccommodated emmetropic eye the curvature ofthe lens is such that distant objects are sharply imaged on the retina.In the unaccommodated eye near objects are not focused sharply on theretina because their images lie behind the retinal surface. In order tovisualize a near object clearly, the curvature of the crystalline lensis increased, thereby increasing its refractive power and causing theimage of the near object to fall on the retina.

The change in shape of the crystalline lens is accomplished by theaction of certain muscles and structures within the eyeball or globe ofthe eye. The lens is located in the forward part of the eye, immediatelybehind the pupil. It has the shape of a classical biconvex optical lens,i.e., it has a generally circular cross section having two convexrefracting surfaces, and is located generally on the optical axis of theeye, i.e., a straight line drawn from the center of the cornea to themacula in the retina at the posterior portion of the globe. In theunaccommodated human eye the curvature of the posterior surface of thelens, i.e., the surface adjacent to the vitreous body, is somewhatgreater than that of the anterior surface. The lens is closelysurrounded by a membranous capsule that serves as an intermediatestructure in the support and actuation of the lens. The lens and itscapsule are suspended on the optical axis behind the pupil by a circularassembly of very many radially directed elastic fibers, the zonules,which are attached at their inner ends to the, lens capsule and at theirouter ends to the ciliary body and indirectly to the ciliary muscle, amuscular ring of tissue, located just within the outer supportingstructure of the eye, the sclera. The ciliary muscle is relaxed in theunaccommodated eye and therefore assumes its largest diameter. Accordingto the classical theory of accommodation, originating with Helmholtz,the relatively large diameter of the ciliary muscle in this conditioncauses a tension on the zonules which in turn pulls radially outward onthe lens capsule, causing the equatorial diameter of the lens toincrease slightly and decreasing the anterior-posterior dimension of thelens at the optical axis. Thus, the tension on the lens capsule causesthe lens to assume a flattened state wherein the curvature of theanterior surface, and to some extent the posterior surface, is less thanit would be in the absence of the tension. In this state the refractivepower of the lens is relatively low and the eye is focused for clearvision for distant objects.

When the eye is intended to be focused on a near object, the ciliarymuscles contract. According to the classical theory, this contractioncauses the ciliary muscle to move forward and inward, thereby relaxingthe outward pull of the zonules on the equator of the lens capsule. Thisreduced zonular tension allows the elastic capsule of the lens tocontract causing an increase in the anterior-posterior diameter of thelens (i.e., the lens becomes more spherical) resulting in an increase inthe optical power of the lens. Because of topographical differences inthe thickness of the lens capsule, the central anterior radius ofcurvature decreases more than the central posterior radius of curvature.This is the accommodated condition of the eye wherein the image of nearobjects falls sharply on the retina.

Presbyopia is the universal decrease in the amplitude of accommodationthat is typically observed in individuals over forty years of age. Inthe person having normal vision, i.e., having emmetropic eyes, theability to focus on near objects is gradually lost, and the individualcomes to need glasses for tasks requiring near vision, such as reading.

According to the conventional view the amplitude of accommodation of theaging eye is decreased because of the loss of elasticity of the lenscapsule and/or sclerosis of the lens with age. Consequently, even thoughthe radial tension on the zonules is relaxed by contraction of theciliary muscles, the lens does not assume a greater curvature. Accordingto the conventional view, it is not possible by any treatment to restorethe accommodative power to the presbyopic eye. The loss of elasticity ofthe lens and capsule is seen as irreversible, and the only solution tothe problems presented by presbyopia is to use corrective lenses forclose work, or bifocal lenses, if corrective lenses are also requiredfor distant vision.

Contrary to the conventional view, it is possible to restore theaccommodative power to a. presbyopic eye by implanting a plurality ofscleral prostheses within the sclera of the eye. For each individualscleral prosthesis an incision is made in the sclera of the globe of theeye near the plane of the equator of the crystalline lens. The incisionis then extended under the surface of the sclera to form a scleral“pocket.” The scleral prosthesis is then placed within the pocket. Atypical scleral prosthesis comprises a generally rectangularly shapedbar approximately five millimeters (5.0 mm) long, one and one halfmillimeters (1.5 mm) wide, and one millimeter (1.0 mm) tall. Theanterior edge of the scleral prosthesis applies an outward force on theanterior edge of the scleral pocket which elevates the anterior portionof the sclera attached thereto and the ciliary body immediately beneaththe sclera to increase the working distance of the ciliary muscle. Thismethod is described more fully in the A Presbyopia and Related EyeDisorder Patent Documents that have been incorporated by reference intothis patent document.

A physician who makes the incisions to form a scleral pocket must be avery skilled surgeon. The surgeon must use great care to ensure that theincisions are made properly. The incisions that must be made to form ascleral pocket are quite small. The incisions must be made at preciselythe correct depth. The width and length of the scleral pocket must alsobe formed by precise incisions.

It is well known that physicians may differ significantly with respectto the level of surgical skill that they possess. Physicians whopractice surgery regularly generally become quite skilled. Otherphysicians who do not practice surgery regularly are less skilled. Evenskilled surgeons may find it difficult to make the precise incisionsthat are required to correctly form a scleral pocket.

If scleral pocket incisions are not made with sufficient precision theresulting scleral pocket will not be able to correctly support a scleralprosthesis. An incorrectly supported scleral prosthesis is not able toprovide an acceptable level of vision correction.

It would be desirable if a system and method existed that would allow asurgeon to make the precise incisions that are required to form ascleral pocket. Accordingly, a need exists in the art for a system andmethod that is capable of making the precise incisions within the scleraof an eye to form a scleral pocket to receive a scleral prosthesis.

SUMMARY OF THE INVENTION

The system and method of the present invention comprises a surgical toolthat is capable of making incisions within the sclera of an eye to forma scleral pocket to receive a scleral prosthesis.

An advantageous embodiment of the surgical tool of the present inventioncomprises a base housing and a drive shaft housing. The base housing ofthe surgical tool receives electrical power and control signals from anexternal surgical tool controller. The drive shaft housing comprises ablade mount housing that is mounted on the drive shaft housing at anangle to a central axis of the drive shaft housing. A surgical blade formaking incisions in the sclera of an eye is mounted on the blade mounthousing.

A surgeon,positions the surgical blade of the surgical tool over thesclera of an eye by aligning an external reference line on the blademount housing with the limbus of the eye. The surgeon then places theblade mount housing on the sclera of the eye. A pressure sensordetermines when there is sufficient pressure between the surgical tooland the sclera of the eye for the surgical tool to operate properly.When the pressure sensor detects sufficient pressure the surgical toolmay be activated. The surgeon sends an activation signal to the surgicaltool to cause the surgical blade to advance through the sclera to forman incision having dimensions to receive a scleral prosthesis. Thesclera of the eye and the surgical tool are restrained from moving whilethe surgical blade is moved through the sclera to make an incision. Whenthe incision is complete the surgical blade is moved back out of theincision. The incision then has the exact dimensions to receive ascleral prosthesis.

It is an object of the invention to provide a surgical tool that iscapable of making precise incisions in the sclera of an eye to create ascleral pocket that has exact dimensions to receive a scleralprosthesis.

It is an additional object of the invention to provide a surgical toolcontroller for controlling the operation of a surgical blade of asurgical tool for making incisions in the sclera of an eye to create ascleral pocket.

It is yet another object of the invention to provide an improvedsurgical blade for making incisions in the sclera of an eye to create ascleral pocket.

It is also another object of the present invention to provide animproved blade guide for guiding the motion of a surgical blade in thesurgical tool of the present invention.

It is a further object of the present invention to provide a scleraltissue fixation tool that is capable of restraining the movement of thesclera of the eye away from the surgical blade of the surgical tool ofthe present invention when an incision is being made in the sclera ofthe eye.

It is another object of the present invention to provide a vacuumoperated blade guide that is capable of restraining the movement of thesclera of the eye away from the surgical blade of the surgical tool ofthe present invention by applying a vacuum to the surface of the scleraof the eye.

It is yet another object of the present invention to provide an improvedsurgical blade of the surgical tool of the present invention that iscapable of implanting a scleral prosthesis in a scleral pocket of aneye.

Additional objects of the present invention will become apparent fromthe description of the invention that follows.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention so that those skilled in the art maybetter understand the Detailed Description of the Invention thatfollows. Additional features and advantages of the invention will bedescribed hereinafter that form the subject matter of the claims of theinvention. Those skilled in the art should appreciate that they mayreadily use the conception and the specific embodiment disclosed as abasis for modifying or designing other structures for carrying out thesame purposes of the present invention. Those skilled in the art shouldalso realize that such equivalent constructions do not depart from thespirit and scope of the invention in its broadest form.

Before undertaking the Detailed Description of the Invention, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The terms “include” and “comprise,” andderivatives thereof, mean inclusion without limitation; the term “or” isinclusive, meaning “and/or”; the phrases “associated with” and“associated therewith,” as well as derivatives thereof, may mean toinclude, be included within, interconnect with, contain, be containedwithin, connect to or with, couple to or with, be communicable with,cooperate with, interleave, juxtapose, be proximate to, to bound to orwith, have, have a property of, or the like; and the term “controller,”“processor,” or “apparatus” means any device, system or part thereofthat controls at least one operation. Such a device may be implementedin hardware, firmware or software, or some combination of at least twoof the same. It should be noted that the functionality associated withany particular controller may be centralized or distributed, whetherlocally or remotely. Definitions for certain words and phrases areprovided throughout this patent document. Those of ordinary skill shouldunderstand that in many instances (if not in most instances), suchdefinitions apply to prior uses, as well as to future uses, of suchdefined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an isometric view of an eye having scleral pockets forreceiving scleral prostheses;

FIG. 2 shows a front elevational view of an eye showing the location offour straight scleral pockets;

FIG. 3 shows a cross section of the eye of FIG. 2 along the line 3-3;

FIG. 4 shows an enlarged view of the cross section of FIG. 3 in theregion indicated by the circle 4;

FIG. 5 shows a top plan view of an exemplary scleral prosthesis;

FIG. 6 shows a front. elevational view of the scleral prosthesis shownin FIG. 5 showing the contoured profile of the prosthesis and twonotches in-the bottom of the prosthesis;

FIG. 7 shows a bottom plan view of the scleral prosthesis shown in FIG.5 showing the location of two notches in the bottom of the prosthesis;

FIG. 8 shows an end view of the scleral prosthesis shown in FIG. 5;

FIG. 9 shows a top perspective view of the scleral prosthesis shown inFIG. 5 showing the top and one side and one end of the prosthesis;

FIG. 10 shows a bottom perspective view of the scleral prosthesis shownin FIG. 5 showing the bottom and one side of the prosthesis;

FIG. 11 shows a perspective view of a surgical tool constructed inaccordance with the principles of the present invention for makingincisions in the sclera of an eye to create a scleral pocket to receivea scleral prosthesis;

FIG. 12 shows a surgical tool controller for controlling the operationof the surgical tool of the present invention and a foot switch foractivating the surgical tool;

FIG. 13 shows an end view of the surgical tool of the present inventionshowing a control cable receptacle capable of receiving a control cableto supply electrical power to the surgical tool;

FIG. 14 shows a cross section of a first portion of the surgical tool ofthe present invention showing a base housing containing a control cablereceptacle, a drive motor, a gearbox, and a drive shaft capable of beingrotated by the drive motor;

FIG. 15 shows a schematic circuit diagram illustrating how electricalpower is supplied to the drive motor of the surgical tool;

FIG. 16 shows a cross section of a second portion of the surgical toolshowing a drive shaft housing mounted within an end of the base housingof the surgical tool, and showing a blade mount housing mounted on thedrive shaft housing an angle to a central axis of the drive shafthousing;

FIG. 17 shows a more detailed cross sectional view of theinterconnection of the drive shaft housing and the blade mount housingshown in FIG. 16;

FIG. 18 shows a top plan view of a blade of the surgical tool of thepresent invention;.

FIG. 19 shows a side view of the blade shown in FIG. 18;

FIG. 20 shows a perspective view of the blade shown in FIG. 18;

FIG. 21 shows a side view of the drive shaft housing and the blade mounthousing and the blade of the surgical tool of the present invention;

FIG. 22 shows a perspective view of the drive shaft housing and an endview of the blade mount housing of the surgical tool of the presentinvention;

FIG. 23 shows a top view illustrating how the surgical tool of thepresent invention is to be positioned over an eye to make incisions inthe sclera of the eye;

FIG. 24 shows a side view illustrating how the surgical tool of thepresent invention is to be positioned over an eye to make incisions inthe sclera of the eye;

FIG. 25 shows a perspective view of an alternate advantageous embodimentof a blade guide of the surgical tool of the present invention to guidethe motion of a blade when the blade is rotated to make incisions in thesclera of an eye;

FIG. 26 shows an end view of the blade guide shown in FIG. 25;

FIG. 27 shows an end view of the blade mount housing and blade guide andblade placed in contact with an eye showing how a blade passes throughthe blade guide when the blade is rotated to make incisions in thesclera of an eye;

FIG. 28 shows a side view of an end portion of the blade mount housingshowing a portion of the blade guide that is placed in contact with aneye during the process of making incisions in the sclera of the eye;

FIG. 29 shows how a blade moves through the blade guide shown in FIG. 28during the process of making incisions in the sclera of the eye;

FIG. 30 shows and exemplary scleral tissue fixation tool of the presentinvention;

FIG. 31 shows a perspective view of an advantageous embodiment of afixation end of a scleral tissue fixation tool of the present invention;

FIG. 32 shows a side view of an alternate advantageous embodiment of afixation end of a scleral tissue fixation tool of the present invention;

FIG. 33 shows a side view of an alternative advantageous embodiment of ablade guide of the surgical tool of the present invention comprising aninterior vacuum chamber;

FIG. 34 shows a perspective view of the blade guide shown in FIG. 33;

FIG. 35 shows a side view of an alternative advantageous embodiment of ablade guide of the surgical tool of the present invention comprising aninterior vacuum chamber showing the operation of the vacuum chamberblade guide;

FIG. 36 shows a perspective view of a vacuum supply line coupled to thevacuum chamber blade guide of the present invention;

FIG. 37 shows a perspective view of the surgical tool of the presentinvention showing the placement of a vacuum supply line along thesurgical tool;

FIG. 38 shows a flow chart of an advantageous embodiment of a method ofthe present invention for making incisions to form a scleral pocket fora scleral prosthesis;

FIG. 39 shows a flow chart of an alternate advantageous embodiment of amethod of the present invention for making incisions to form a scleralpocket for a scleral prosthesis;

FIG. 40 shows a first perspective view of an alternate advantageousembodiment of a blade of the surgical tool of the present invention;

FIG. 41 shows a second perspective view of an alternate advantageousembodiment of a blade of the surgical tool of the present invention;

FIG. 42 shows how a scleral prosthesis may be tied to an extension of analternate advantageous embodiment of a blade of the surgical tool of thepresent invention;

FIG. 43 shows a first perspective view of a second alternateadvantageous embodiment of a blade of the surgical tool of the presentinvention;

FIG. 44 shows a second perspective view of a second alternateadvantageous embodiment of a blade of the surgical tool of the presentinvention;

FIG. 45 shows a side view of three portions of a curved cutting blade ofthe second alternate advantageous embodiment of a blade of the surgicaltool of the present invention;

FIG. 46 shows a first perspective view of a third alternate advantageousembodiment of a blade of the surgical tool of the present invention;

FIG. 47 shows a second perspective view of a third alternateadvantageous embodiment of a blade of the surgical tool of the presentinvention; and

FIG. 48 shows a cross sectional side view of a curved cutting blade ofthe third alternate advantageous embodiment of a blade of the surgicaltool of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 through 48, discussed below, and the various embodiments used todescribe the principles of the present invention in this patent documentare by way of illustration only and should not be construed in any wayto limit the scope of the invention. Those skilled in the art willunderstand that the principles of the present invention may beimplemented in any suitably arranged surgical tool and with any suitablesurgical method.

The system and method of the present invention comprise a surgical toolthat is capable of making incisions in the sclera of an eye in order forthe eye to receive a scleral prosthesis. Scleral prostheses are used totreat presbyopia (and other similar eye disorders) by increasing theeffective working distance of the ciliary muscle of the eye. This isaccomplished by increasing the distance between the ciliary muscle andthe lens equator by increasing the diameter of the sclera in the regionof the ciliary body.

The effective working distance of the ciliary muscle is increased byimplanting in pockets surgically formed in the sclera of the eye aplurality of scleral prostheses designed to place an outward traction onthe sclera in the region of the ciliary body. The relevant anatomy ofthe eye for locating the scleral pockets may be seen by reference toFIGS. 1-4. The outermost layer of the eye 100 comprises the white, toughsclera 102 which encompasses most of the globe and the transparentcornea 104, which constitutes the anterior segment of the outer coat.The circular junction of the cornea and sclera is the limbus 106. Withinthe globe of the eye, as illustrated in the cross-section shown in FIG.3, the crystalline lens 108 is enclosed in a thin membranous capsule andis located immediately posterior to the iris 112, suspended centrallyposterior to the pupil 114 on the optical axis of the eye. The lens 108is suspended by zonules 115 extending between the lens capsule at theequator 110 of the lens 108 and the ciliary body 116. The ciliary body116 lies just under the sclera 102 (i.e., just inwardly of the sclera102) and is attached to the inner surface of the sclera 102. As may beseen in FIG. 3i the ciliary body 116 lies generally in a plane 130defined by the equator 110 of the lens 108. The plane 130 can also beextended to intersect the sclera 102 whereby it forms a generallycircular intersection located about two (2) millimeters posterior to thelimbus 106. The external muscles 118-of the eyeball control the movementof the eye.

A generally outwardly directed traction is exerted on the sclera in theregion of the ciliary body to expand the sclera 102 in that region. Thisexpansion of the sclera 102 produces a corresponding expansion of theattached ciliary body 116 and moves the ciliary body 116 outwardly awayfrom the equator 110 of the lens 108, generally in the plane 130 of theequator 110 of the lens 108. The sclera 102 is preferably expandedapproximately in the plane of the equator 110 of the lens 108. However,any expansion of the sclera 102 in the region of the ciliary body 116,i.e., in the region of the sclera somewhat anterior or posterior to theplane of the equator 110 of the lens 108 is within the scope of theinvention, provided that such expansion of the sclera 102 moves theciliary body 116 away from the equator 110 of the lens 108. Typically,the expansion of the sclera will be accomplished in the region fromabout one and one half millimeters (1.5 mm) anterior to the plane 130 ofthe equator 110 of the lens 108 to about two and one half millimeters(2.5 mm) posterior to that plane, i.e., from about one half millimeter(0.5 mm) to about four and one half millimeters (4.5 mm) posterior tothe limbus 106. Accordingly, the anterior margin 122 of a scleral pocket120 will be located in that region of the sclera.

An exemplary scleral pocket 120 is illustrated in FIG. 1. An incision ismade in the surface of sclera 120 along the line indicated withreference numeral 130. The incision is then extended under the surfaceof sclera 120 between the-anterior margin 122 and the posterior margin124 of scleral pocket 120. This forms a “pocket” under the surface ofsclera 102. The incision may also be extended through the surface ofsclera 102 along the line indicated with reference number 132. Thisforms a “belt loop” type structure in the surface of sclera 102. Forconvenience the “pocket” type structure and the “belt loop” typestructure will both be referred to as scleral pocket 120.

The scleral prosthesis 200 is designed to be placed within scleralpocket 120. Scleral prosthesis 200 within scleral pocket 120 applies anoutwardly directed traction to the sclera 102 at the general position ofthe anterior margin 122 of the scleral pocket 120. The position ofprosthesis 200 within scleral pocket 120 and its operation to expand thesclera are illustrated in FIGS. 3 and 4.

An advantageous embodiment of eye implant prosthesis 200 is illustratedin FIGS. 5-10. FIG. 5 shows a plan view of the top 500 of prosthesis200. In one advantageous embodiment, the length of prosthesis 200 isapproximately five thousand five hundred microns (5500 μm) or,equivalently, approximately five and one half millimeters (5.5 mm).

FIG. 6 shows a front elevational view of the prosthesis 200 of FIG. 5showing one side 600 of prosthesis 200. In one advantageous embodiment,the maximum height of prosthesis 200 is approximately nine hundredtwenty five microns (925 μm) or, equivalently, approximately ninehundred twenty five thousandths of a millimeter (0.925 mm). A firstnotch 610 is located in the base 620 of prosthesis 200 at a first end ofprosthesis 200. A second notch 630 is located in the base 620 ofprosthesis 200 at a second end of prosthesis 200. When prosthesis 200 islocated within scleral pocket 120 intraocular pressure from the interiorof eye 100 pushes scleral tissue into notch 610 and into notch 630. Thepresence of scleral tissue in notch 610 and in notch 630 provides ananchoring mechanism that tends to prevent movement of prosthesis 200.

FIG. 7 shows a plan view of the bottom 620 of prosthesis 200. Notch 610and notch 630 extend across the bottom 620 of prosthesis 200.

FIG. 8 shows an end view of prosthesis 200 showing one end 800 of theprosthesis 200. In one advantageous embodiment, the width of prosthesis200 is approximately one thousand three hundred eighty microns (1380 μm)or, equivalently, approximately one and three hundred eighty thousandthsmillimeter (1.380 mm).

FIG. 9 shows a perspective top view of prosthesis 200. FIG. 9 shows top500, one side 600 and one end 800 of the prosthesis 200. FIG. 10 shows aperspective bottom view of prosthesis 200. FIG. 10 shows the bottom 620(including notches 610 and 630) and one side 600 of prosthesis 200.

Other types of scleral prosthesis 200 may be used including those typesof prosthesis disclosed in the “Presbyopia and Related Eye DisorderPatent Documents” previously incorporated by reference into this patentdocument.

Scleral prosthesis 200 is made of a material that is sufficiently rigidto exert a force on the sclera sufficient to produce the radialexpansion required by the method of the invention and that isphysiologically acceptable for long-term implantation or contact withthe ocular tissues. Such materials are well-known in the surgical artand include suitable metals, ceramics, and synthetic resins. Suitablemetals include titanium, gold, platinum, stainless steel, nitinol,tantalum and various surgically acceptable alloys, and the like.Suitable ceramics may include crystalline and vitreous materials such asporcelain, alumina, silica, silicon carbide, high-strength glasses andthe like. Suitable synthetic materials include physiologically inertmaterials such as poly(methyl methacrylate), polyethylene,polypropylene, poly(tetrafluoroethylene), polycarbonate, siliconeresins, hydrophilic plastics, hydrophobic plastics, hypoxy-appetite, andthe like. The scleral prosthesis 200 may also be made of compositematerials incorporating a synthetic resin or other matrix reinforcedwith fibers of high strength material such as glass fibers, boron fibersor the like. Thus, scleral prosthesis 200 may be made ofglass-fiber-reinforced epoxy resin, carbon fiber-reinforced epoxy resin,carbon fiber-reinforced carbon (carbon-carbon), or the like. Scleralprosthesis 200 may be made of a semi-rigid exterior and a liquid or gelfilled interior so that the internal and external dimensions can bealtered by injecting various amounts of liquid: water, saline, orsilicone oil; or various amounts of a gel: silicone, collagen, orgelatin. The semi-rigid exterior may be made of any of the alreadylisted materials. A preferred material for the entire scleral prosthesis200 is surgical grade poly(methyl methacrylate). Scleral prosthesis 200may also be made of a material that regains its shape when deformed suchas a memory metal (e.g., nitinol).

Scleral prosthesis 200 may be manufactured by any conventional techniqueappropriate to the material used, such as machining, injection molding,heat molding, compression molding and the like.

Scleral prosthesis 200 may be foldable to facilitate insertion into ascleral belt loop or made in a plurality of parts so that it can beassembled prior to use or may be installed separately to form a completeprosthesis.

To implant scleral prosthesis 200 by hand, the surgeon locates theproper region of the sclera to be expanded by measuring a distance ofpreferably three and one half millimeters (3.5 mm) posterior of thelimbus 106. At two millimeters (2.0 mm) clockwise and counterclockwisefrom each of the forty five degree (45°) meridians of the eye, and threeand one half millimeters (3.5 mm) posterior to the limbus 106, partialscleral thickness parallel incisions, i.e., anterior-posteriorincisions, are made which are one and one half millimeters (1.5 mm) longand three hundred fifty microns (350 μm) deep. Using a lamella blade thesclera is dissected until the partial thickness incisions are connectedso that four scleral pockets or belt loops are made which have ananterior length of four millimeters (4.0 mm), and a length extendinggenerally axially of the eye of one and one half millimeters (1.5 mm).Thus, each pocket or belt loop is preferably centered over the fortyfive degree (45°) meridian of the eye. A scleral prosthesis 200 is theninserted in each of the four scleral belt loops. This producessymmetrical scleral expansion which will produce the desired result ofincreasing the effective working distance of the ciliary muscle.

The location of the scleral prostheses 200 implanted in eye 100 isillustrated in FIGS. 1-4. FIG. 1 is an isometric view of an eye 100having a globe with the relevant exterior anatomical parts indicated asdiscussed above.

FIG. 2 shows a front elevational view of an eye 100 showing the scleralpockets 120 formed at approximately the forty five degree (45°)meridians of the eye, i.e., approximately halfway between the verticaland horizontal meridians of the globe. This location is preferredbecause it avoids interference with structures of the eye that arelocated generally on the vertical and horizontal meridians. FIG. 2 showsthe use of straight scleral pockets 120. Straight scleral pockets 120are somewhat simpler to prepare surgically than curved scleral pockets(not shown). For many patients the use of straight scleral prosthesesprovide adequate treatment of presbyopia. Alternatively, curved scleralprostheses may be used as discussed in the “Presbyopia and Related EyeDisorder Patent Documents” previously incorporated by reference intothis patent document.

FIG. 3 shows a cross-section of eye 100, taken along the line 3-3 inFIG. 2, showing the placement of scleral prosthesis 200 relative to thesignificant anatomical structures of the eye. FIG. 3 shows the generalconfiguration of the scleral pockets 120 and the prostheses 200 of thetype illustrated in FIGS. 5-10. The anterior margins 122 of the scleralpockets 120 are located approximately in the plane 130 of the equator110 of the lens 108. The presence of prosthesis 200 causes the portionof the sclera anterior to the scleral pocket 120 to be expanded somewhatmore than the posterior portion. This places the sclera anterior to thescleral pocket 120 under a radial tension and causes it to expand fromits normal diameter at that position. This scleral expansion draws withit the underlying ciliary body 116 and causes the ciliary body to bedrawn away from the equator 110 of the lens 108. Accordingly, theexpansion of the ciliary body 116 operates to increase the workingdistance of the ciliary muscle and restore, at least in part, theability of the eye to accommodate for clear focusing on objects atdifferent distances.

FIG. 4 shows an enlarged portion of one of the scleral pockets 120 withadjacent anatomical structures. It shows the relation of the scleralpocket 120 to the underlying structures and its location just posteriorto the equator of the lens 108 and overlying the ciliary body 116.

The surgical procedures described above to make incisions within thesclera 102 of eye 100 are done by hand. That is, the surgeon makes theincisions in sclera 102 that are required to form scleral pocket 120using standard surgical tools such as a scalpel. The surgeon must bevery skilled in the use of a scalpel to make incisions that have therequired precision.

However, the system and method of the present invention provide a muchmore efficient and precise way to make the required incisions. Thesystem and method of the present invention comprise a surgical tool thatis specifically designed to make very precise incisions in the sclera102 of an eye 100 to form a scleral pocket 120.

FIG. 11 shows a perspective view of an electromechanical surgical tool1100 constructed in accordance with the principles of the presentinvention. As will be more fully described, surgical tool 1100 iscapable of making incisions in eye 100 to create a scleral pocket 120 toreceive a scleral prosthesis 200. Surgical tool 1100 comprises a basehousing 1110 and a drive shaft housing 1120. Drive shaft housing 1120comprises a blade mount housing 1130 that mounted on the drive shafthousing 1120 an angle to a central axis of drive shaft housing 1120. Thereason for mounting blade mount housing 1130 at an angle with respect tothe central axis of drive shaft housing 1120 is to facilitate theplacement of blade mount housing 1130 on eye 100 during the surgicalprocess. Lastly, blade 1140 is mounted on blade mount housing 1130.

FIG. 12 shows surgical tool 1100 and a surgical tool controller 1200 forcontrolling the operation of surgical tool 1100. Surgical tool 1100 iscoupled to surgical tool controller 1200 through control cable 1210.Control cable 1210 provides electrical power to surgical tool 1100 underthe control of surgical tool controller 1200 to power the operation ofblade 1140. Control cable 1210 also provides an “earth ground” tosurgical tool 1100. Surgical tool controller 1200 receives externalelectrical power through power cord 1220. It is also possible to use abattery (not shown) or other power source.

Foot switch 1230 is coupled to surgical tool controller 1200 throughsignal line 1240. When the surgeon is ready to rotate blade 1140 to makean incision in eye 100 the surgeon steps on foot switch 1230. Footswitch 1230 then sends a control signal to surgical tool controller 1200through signal line 1240. In response, surgical tool controller 1220activates electrical power to surgical tool 1100 to cause blade 1140 torotate in a forward direction and make the desired incision in eye 100.In one advantageous embodiment the time required for blade 1140 to makean incision in eye 100 is approximately two (2) seconds. Other suitabletime durations may be appropriate. The incision is complete after blade1140 has reached the end of its rotation in the forward direction.Surgical tool controller 1200 then automatically causes blade 1140 torotate back out of the incision. Surgical tool 1100 is then ready tomake another incision.

If the surgeon releases his or her foot from foot switch 1230 during thetime period during which the incision is being made, foot switch 1230immediately sends a control signal to surgical tool controller 1200through signal line 1240. In response, surgical tool controller 1220causes the forward motion of blade 1140 to cease. If the surgeon stepson foot switch 1230 again blade 1140 resumes its rotation in the forwarddirection. If the surgeon desires to rotate blade 1140 out of theincision the surgeon manually presses a “blade retract” control buttonon surgical tool controller 1200.

Surgical tool controller 1200 comprises a switch 1250 (on/off switch1250) for activating the operation of surgical tool controller 1200.Surgical tool controller 1200 also comprises indicator lights 1260 thatindicate the operational status of surgical tool controller 1200. It isunderstood that other control methods may also be used to control theoperation of surgical tool 1100 such as voice activated controls, handcontrols, finger controls, and other biometric controls.

FIG. 13 shows an end view of base housing 1110 of surgical tool 1100.Base housing 1110 comprises a control cable receptacle 1300 capable ofreceiving control cable 1210 to electrically power surgical tool 1100.In this advantageous embodiment control cable receptacle 1300 is capableof receiving four (4) individual power plugs of control cable 1210.

FIG. 14 shows a cross section of base housing 1110. Base housing 1110comprises control cable receptacle 1300, four power lines (collectivelydesignated 1410), drive motor 1420, gearbox 1430, and a drive shaft1440. When control cable 1210 is placed into control cable receptacle1300, four power plugs of control cable 1210 make contact with the fourpower lines 1410. As shown in FIG. 15, two of the four power lines (line1 and line 2) are coupled to a first winding circuit (circuit A) ofmotor 1420. The other two of the four power lines (line 3 and line 4)are coupled to a second winding circuit (circuit B) of motor 1420.

When surgical tool controller 1200 powers up line 1 and line 2, thenmotor 1420 rotates in one direction (e.g., counterclockwise). Whensurgical tool controller 1200 powers up line 3 and line 4, then motor1420 rotates in the other direction (e.g., clockwise). In this mannermotor 1420 provides both rotational motion to-rotate blade 1140 forwardto make an incision in eye 100 and provides rotational motion to rotateblade 1140 backwards to remove blade 1140 from the incision made in eye100. The two types of rotational motion will be collectively referred toas “bidirectional rotational motion.”

The rotational motion generated by motor 1420 is coupled to gearbox1430. In one advantageous embodiment gearbox 1430 reduces the rotationalspeed provided by motor 1420 by a factor of sixty six (66:1). That is,the rotational speed output by gearbox 1430 is one sixty sixth ( 1/66)of the rotational speed provided to gearbox 1430 by motor 1420. Thisamount of rotational speed reduction is necessary to increase the torqueand because the rotational speed provided by motor 1420 is too great tobe used to rotate blade 1140 directly. The rotational output fromgearbox 1430 is coupled to drive shaft 1440 of base housing 1110.

FIG. 16 shows a cross sectional view of drive shaft housing 1120 mountedwithin base housing 1110 and a cross sectional view of blade mounthousing 1130. Blade 1140 is not shown in FIG. 16. Drive shaft housing1120 seats within a receptacle of base housing 1110 and is held in placeby conventional means such as a screw 1610. O-ring 1620 seals thejuncture between the receptacle of base housing 1110 and drive shafthousing 1120.

Drive shaft housing 1120 comprises drive shaft 1630. Drive shaft 1630 issupported within drive shaft housing 1120 by conventional bearings. Asshown in FIG. 16, drive shaft 1630 is coupled to drive shaft 1440 ofbase housing 1110. The coupling of drive shaft 1630 and drive shaft 1440is supported by conventional bearings. Drive shaft 1440 rotates driveshaft 1630.

Blade mount housing 1130 comprises drive shaft 1640. Drive shaft 1640 issupported within blade mount housing 1130 by conventional bearings. Asshown in FIG. 16, drive shaft 1640 is coupled to drive shaft 1630 ofdrive shaft housing 1120 at an angle. As shown in greater detail in FIG.17, a beveled gear 1710 of drive shaft 1630 engages a beveled gear 1720of drive shaft 1640. As drive shaft 1630 is rotated, the rotationalmotion of beveled gear 1720 of drive shaft 1630 is imparted to beveledgear 1720 of drive shaft 1640. The rotational motion of drive shaft 1640is used to rotate blade 1140 (not shown in FIGS. 16 and 17) mounted onblade mount housing 1130.

Base plate 1730 seats within an end of blade mount housing 1130 and isheld in place by conventional means such as a screw 1740. Drive shaft1640 extends through an aperture in base plate 1730 so that base plate1730 also provides support for drive shaft 1640. Conventional means suchas a screw 1750 may be used to secure blade 1140 to drive shaft 1640.Screw 1750 may also serve as an extension 1750 of drive shaft 1640 ontowhich blade 1140 may be mounted. Base-plate 1730 comprises portionsforming a blade guide 1760 for guiding the rotation of blade 1140 andfor stopping the rotation of blade 1140 after blade 1140 has beenrotated by a desired amount.

The blade 1140 of surgical tool 1100 is shown in FIGS. 18-20. FIG. 18shows a top plan view of blade 1140. FIG. 19 shows a side view of blade1140. FIG. 20 shows a perspective view of blade 1140. Blade 1140comprises support arm 1810 adapted to be mounted on an end of driveshaft 1640 of blade mount housing 1130. Blade 1140 also comprises acurved cutting blade 1820 for making an incision in the sclera 102 ofeye 100. In an advantageous embodiment of the invention, (1) support arm1810 and curved cutting blade 1820 are formed as a unitary structure,and (2) curved cutting blade 1820 is circularly curved, and (3) curvedcutting blade 1820 has end portions defining a tapered cutting point1830.

When drive shaft 1640 is rotated, support arm 1810 rotates around theaxis of drive shaft 1640. This causes curved cutting blade 1820 torotate around the axis of drive shaft 1640. The dimensions of curvedcutting blade 1820 are chosen so that the incision made by curvedcutting blade 1820 in the sclera 102 of eye 100 has the desireddimensions to form scleral pocket 120. Scleral pocket 120 should beapproximately four millimeters (4.0 mm) long, one and one halfmillimeters (1.5 mm) wide, and four hundred microns (400 μm) deep. Fourhundred microns (400 μm) is equivalent to four tenths of a millimeter(0.4 mm).

FIG. 21 shows an external side view of drive shaft housing 1120 andblade mount housing 1130 and blade 1140. Aperture 2110 is provided toreceive screw 1610 to fasten drive shaft housing 1120 within basehousing 1110. Groove 2120 is provided to receive O-ring 1620 to seal the juncture between the receptacle of base housing 1110 and drive shafthousing 1120. Aperture 2130 is provided to receive screw 1740 to fastenbase plate 1730 within blade mount housing 1130.

An external reference line 2140 is marked on the surface of blade mounthousing 1130. Line 2140 is located five and one half millimeters (5.5mm) from the end of blade mount housing 1130. Line 2140 allows thesurgeon to properly align blade 1140 during the surgical process. Thesurgeon aligns line 2140 with the limbus 106 of eye 100. This alignmentproperly positions blade 1140 to make an incision at the desiredlocation on sclera 102 of eye 100.

FIG. 22 shows a perspective view of drive shaft housing 1120 and an endview of blade mount housing 1130. Base plate 1730 forms the end of blademount housing 1130. The components of blade 1140 are shown separately assupport arm 1810 and curved cutting blade 1820. Support arm 1810 ismounted on drive shaft 1640 by snapping an end of support arm 1810 ontoan extension 1750 of drive shaft 1640. In an alternative embodiment,support arm 1810 may be mounted on drive shaft 1640 using conventionalmeans such as a screw.

Support arm 1810 is shown rotated forward to a position where it hasabutted an edge of blade guide 1760. In this position curved cuttingblade 1820 has completed its rotation and would have completed anincision if it has been adjacent to eye 100. Blade guide 1760 alsoguides the rotation of blade 1140. Blade guide 1760 is formed having acircularly shaped surface 2220 that is concentric with curved cuttingblade 1820. The length of support arm 1810 supports curved cutting blade1820 at a distance that is approximately four hundred microns (400 μm)away from the circularly shaped surface 2220 of blade guide 1760.

At the start of the surgical process the surgeon places the circularlyshaped surface 2220 of blade guide 1760 on the sclera 102 of eye 100.The surgeon then begins the rotation of blade 1140 by stepping on footswitch 1230. As long as the surgeon is stepping on foot switch 1230blade 1140 continues to advance in a forward direction as support arm1810 of blade 1140 rotates curved cutting blade 1820. Curved cuttingblade 1820 then passes through sclera 102 of eye 100 at a depth ofapproximately four hundred microns (400 μm) to make the desiredincision. The surgeon removes his or her foot from foot switch 1230 ifthe surgeon determines that it is desirable to stop the rotation ofblade 1140. Surgical tool controller 1200 will immediately stop therotation of blade 1140 and will then automatically rotate blade 1140 outof the incision.

The components of blade 1140 (support arm 1810 and curved cutting blade1820) may also be rotated back to abut the safety stop 2210. Blade guide1760 and safety stop 2210 limit the rotational range of blade 1140 toonly the rotation needed to perform the desired incisions.

FIG. 23 shows a top view illustrating how surgical tool 1100 is to bepositioned over eye 100 to make incisions in the sclera 102 of eye 100.Eye 100 comprises sclera 102, iris 112, pupil 114, and limbus 106 (theboundary between sclera 102 and iris 112). Iris 114 and portions oflimbus 106 are shown in dotted outline in FIG. 23 because they areobscured by drive shaft housing 1120 and blade mount housing 1130. Aspreviously mentioned, the surgeon aligns line 2140 on blade mounthousing 1130 with the limbus 106 of eye 100. This alignment properlypositions blade 1140 to make an incision at the desired location onsclera 102 of eye 100.

FIG. 24 shows a side view illustrating how surgical tool 1100 is to bepositioned over eye 100 to make incisions in the sclera 102 of eye 100.The surgeon aligns line 2140 on blade mount housing 1130 with limbus 106of eye 100. As described with reference to FIG. 23 this alignmentproperly positions blade 1140. The reason for mounting blade mounthousing 1130 at an angle with respect to the central axis of drive shafthousing 1120 is now apparent. It is to facilitate the placement of blademount housing 1130 on eye 100 during the surgical process.

FIG. 25 shows a perspective view of an alternate advantageous embodiment2500 of blade guide 1760. Blade guide 2500 is mounted on base plate1730. In this embodiment blade guide 2500 comprises an end portion 2510forming a first blade slot 2520 on a first end of blade guide 2500.Blade guide 2500 also comprises an end portion 2530 forming a secondblade slot 2540 on a second end of blade guide 2500. Blade guide 2500operates in the same manner as blade guide 1760 except that the endportions, 2510 and 2530, of blade guide 2500 provide additional externalprotection for curved cutting blade 1820 of blade 1140. End portions,2510 and 2530, may also be seated against sclera 102 of eye 100 duringthe surgical process to provide additional peripheral contact betweenblade guide 2500 and sclera 102 and to ensure a proper length for anincision.

FIG. 26 shows an end view of blade guide 2500. Blade guide 2500 isformed having a circularly shaped surface 2550 that is concentric withcurved cutting blade 1820. The length of support arm 1810 supportscurved cutting blade 1820 at a distance that is approximately fourhundred microns (400 μm) away from the circularly shaped surface 2550 ofblade guide 2500.

At the start of the surgical process the surgeon places circularlyshaped surface 2550 of blade guide 2500 on the sclera 102 of eye 100. Apressure sensor 2560 within blade guide 2500 senses the pressure of thesclera 102 against the circularly shaped surface 2550 of blade guide2500. A pressure sensor control line (not shown) connects pressuresensor 2560 to surgical tool controller 1200. Pressure sensor 2560senses whether there is sufficient pressure between the surface ofsclera 102 and the circularly shaped surface 2550 of blade guide 2500.If there is not sufficient pressure then any incision made by blade 1140would be too shallow. If pressure sensor 2560 does not detect sufficientpressure then surgical tool controller.1200 will not allow blade 1140 ofsurgical tool 1100 to rotate. If pressure sensor 2560 does detectsufficient pressure then surgical tool controller 1200 will allow blade1140 of surgical tool 1100 to rotate.

The surgeon begins the rotation of blade 1140 by stepping on foot switch1230. As long as the surgeon is stepping on foot switch 1230 blade 1140continues to advance in a forward direction as support arm 1810 of blade1140 rotates curved cutting blade 1820. Curved cutting blade 1820 thenpasses through sclera 102 of eye 100 at a depth of approximately fourhundred microns (400 μm) to make the desired incision. The surgeonremoves his or her foot from foot switch 1230 if the surgeon determinesthat it is desirable to stop the rotation of blade 1140. Surgical toolcontroller 1200 will immediately cause the forward motion of blade 1140to cease. If the surgeon steps on foot switch 1230 again blade 1140resumes it rotation in the forward direction. If the surgeon desires torotate blade 1140 out of the incision the surgeon manually presses a“blade retracted” control button on surgical tool controller 1200.

FIG. 27 shows an end view of blade guide 2500 showing how curved cuttingblade 1820 passes through first blade slot 2520 of blade guide 2500, andthrough sclera 102 of eye 100, and through second blade slot 2540 ofblade guide 2500 when support arm 1810 of blade 1140 is rotated. Curve2710 represents the surface contour of sclera 102 of eye 100 beforeblade guide 2500 is placed in contact with eye 100. Curve 2720represents the surface contour of eye 100 after blade guide 2500 isplaced in contact with sclera 102 of eye 100. Pressure applied to keepblade guide 2500 in contact with sclera 102 of eye 100 temporarily makesthe surface contour of the sclera 102 of eye 100 concave during theincision process.

FIG. 28 shows a side view of an end portion of blade mount housing 1130showing the surface 2550 of blade guide 2500 that is placed in contactwith sclera 102 of eye 100. Pressure sensor 2560 in blade guide 250.0 isshown in dotted outline. In this view curved cutting blade 1820 of blade1140 is retracted. First blade slot 2520 and second blade slot 2540 ofblade guide 2500 are visible.

FIG. 29 also shows a side view of an end portion of blade mount housing1130 showing the surface 2550 of blade guide 2500 that is placed incontact with sclera 102 of eye 100. As before, pressure sensor 2560 inblade guide 2500 is shown in dotted outline. In this view curved cuttingblade 1820 of blade 1140 has begun to be rotated through first bladeslot 2520. Curved cutting blade 1820 is the process of rotating acrosssurface 2550 of blade guide 2500 and is proceeding toward second bladeslot 2540 of blade guide 2500. FIG. 29 shows how curved cutting blade1820 moves through blade guide 2500 during the process of makingincisions in sclera 102 of eye 100.

The counterclockwise motion of the curved cutting blade 1820 hitting thesurface of the sclera 102 of eye 100 tends to push surgical tool 1100 inthe opposite direction causing surgical tool 1100 to translate oppositeto the tangent force generated by curved cutting blade 1820. It istherefore necessary to firmly hold the surface of the sclera 102 againstthe surgical tool 1100 during the process of making the incision.

In one advantageous embodiment of the invention, a scleral tissuefixation tool 3000 is utilized to restrain the movement of surgical tool1100. As shown in FIG. 30, scleral tissue fixation tool 3000 generallycomprises a shaft 3010 having a fixation end 3020 that is capable ofengaging and holding a portion of the surface of sclera 102. Scleraltissue fixation tool 3000 applies a force opposite to the tangent forcegenerated by the curved cutting blade 1820 coming in contact with thesclera 102. The shaft 3010 is manually held and operated by the surgeonduring the process of making an incision so that surgical tool 1100 doesnot move.

In one advantageous embodiment, scleral tissue fixation tool 3000 isapproximately fifteen centimeters (15.0 cm) to twenty centimeters (20.0cm) long and approximately one and one half millimeters (1.5 mm) wide.FIG. 31 shows a perspective view of fixation end 3020 of scleral tissuefixation tool 3000. Fixation end 3020 comprises a first fixation barb3110 formed on a first side of the end of shaft 3010. First fixationbarb 3110 is formed by slicing and lifting up an end portion of shaft3010. The amount of separation of first fixation barb 3110 from the endof shaft 3010 is in the range from three tenths of a millimeter (0.30mm) to four tenths of a millimeter (0.40 mm).

Fixation end 3020 also comprises a second fixation barb 3120 formed on asecond side of the end of shaft 3010. Second fixation barb 3120 isformed by slicing and lifting up an end portion of shaft 3010. Theamount of separation of second fixation barb 3120 from the end of shaft3010 is the same as the amount of separation of first fixation barb3110.

To restrain the translational movement of surgical tool 1100 the surgeonuses scleral tissue fixation tool 3000 to engage and hold a portion ofsclera 102 near the first blade slot 2520 of blade guide 2500. Firstblade slot 2520 is where curved cutting blade 1820 first impacts sclera102 and tends to cause translation of surgical tool 1100. The surgeonplaces the fixation end 3020 of the scleral tissue fixation tool 3000onto the sclera 102 and twists shaft 3010 to the right to engage firstfixation barb 3110 and second fixation barb 3120 into sclera 102. Thesurgeon holds the shaft 3010 against surgical tool 1100 during theincision process. After the incision has been made the surgeon releasesthe scleral tissue fixation tool 3000 from sclera 102 by twisting shaft3010 to the left to disengage the grip of fixation barbs, 3110 and 3120.

The scleral tissue fixation tool 3000 shown in FIG. 31 is a “righttwist” tool. It engages by twisting shaft 3010 to the right anddisengages by twisting shaft 3010 to the left.

FIG. 32 shows an alternative advantageous embodiment of scleral tissuefixation tool 3000. The scleral tissue fixation tool 3000 shown in FIG.32 is a “left twist” tool. It engages by twisting shaft 3010 to the leftand disengages by twisting shaft 3010 to the right. Otherwise, thescleral tissue fixation tool 3000 shown in FIG. 32 is identical to thescleral tissue fixation tool 3000 shown in FIG. 31. It comprises a firstfixation barb 3210 and a second fixation barb 3220. The amount ofseparation 3230 of first fixation barb 3210 from the end of shaft 3010is in the range from three tenths of a millimeter (0.30 mm) to fourtenths of a millimeter (0.40 mm). The amount of separation of secondfixation barb 3220 from the end of shaft 3010 is the same as the amountof separation of first fixation barb 3210.

In an alternate advantageous embodiment of the invention, a special typeof vacuum operated blade guide 3300 is utilized to restrain the movementof the sclera 102 and the translational movement of surgical tool 1100generated from the impact of the curved cutting blade 1820. As will bemore fully described, a vacuum is applied to seat blade guide 330against sclera 102 during the process of making an incision.

FIG. 33 shows an end view of blade guide 3300. Blade guide 3300 ismounted on base plate 1730. In this embodiment blade guide 3300comprises an end portion 3310 forming a first blade slot 3320 on a firstend of blade guide 3300. Blade guide 3300 also comprises an end portion3330 forming a second blade slot 3340 on a second end of blade guide3300. The end portions, 3310 and 3330, of blade guide 3300 provideadditional external protection for curved cutting blade 1820 of blade1140. End portions, 3310 and 3330, are seated against sclera 102 of eye100 during the surgical process to provide additional peripheral contactbetween blade guide 3300 and sclera 102 to ensure proper scleral pocketlength.

Blade guide 3300 is formed having a circularly shaped surface 3350 thatis concentric with curved cutting blade 1820. The length of support arm1810 supports curved cutting blade 1820 at a distance that isapproximately four hundred microns (400 μm) away from the circularlyshaped surface 3350 of blade guide 3300.

At the start of the surgical process the surgeon places circularlyshaped surface 3350 of blade guide 3300 on the sclera 102 of eye 100. Apressure sensor 3390 within blade guide 3300 senses the pressure of thesclera 102 against the circularly shaped surface 3350 of blade guide3300. A pressure sensor control line (not shown) connects pressuresensor 3390 to surgical tool controller 1200. Pressure sensor 3390senses whether there is sufficient pressure between the surface ofsclera 102 and the circularly shaped surface 3350 of blade guide 3300.If there is not sufficient pressure then any incision made by blade 1140would be too shallow. If pressure sensor 3390 does not detect sufficientpressure then surgical tool controller 1200 will not allow blade 1140 ofsurgical tool 1100 to rotate. If pressure sensor 3390 does detectsufficient pressure then surgical tool controller 1200 will allow blade1140 of surgical tool 1100 to rotate.

The surgeon begins the rotation of blade 1140 by stepping on foot switch1230. As long as the surgeon is stepping on foot switch 1230 blade 1140continues to advance in a forward direction as support arm 1810 of blade1140 rotates curved cutting blade 1820. Curved cutting blade 1820 thenpasses through sclera 102 of eye 100 at a depth of approximately fourhundred microns (400 μm) to make the desired incision. The surgeonremoves his or her foot from foot switch 1230 if the surgeon determinesthat it is desirable to stop the rotation of blade 1140. Surgical toolcontroller 1200 will immediately cause the forward motion of blade 1140to cease. If the surgeon steps on foot switch 1230 again blade 1140resumes its rotation in the forward direction. If the surgeon desires torotate blade 1140 out of the incision the surgeon manually presses a“blade retract” control button on surgical tool controller 1200.

Blade guide 3300 also comprises portions that form a vacuum chamber 3360within the interior of blade guide 3300. Blade guide 3300 also comprisesportions that form a plurality of access ports, 3365, 3370, and 3375,that extend from vacuum chamber 3360 through the circularly shapedsurface 3350 of blade guide 3300 to apply vacuum to the surface ofsclera 102. Blade guide 3300 also comprises a vacuum coupling 3380capable of being connected to a vacuum supply line (not shown in FIG.33).

FIG. 34 shows a perspective view of blade guide 3300 showing end portion3310 and first blade slot 3320. FIG. 34 also shows end portion 3330 andsecond blade slot 3340. Vacuum coupling 3380 extends from the exteriorof blade guide 3300 to vacuum chamber 3360 (not shown in FIG. 34)located within blade guide 3300.

FIG. 35 shows an end view of blade guide 3300 showing the placement ofcircularly shaped surface 3350 of blade guide 3300 on the surface ofsclera 102. For clarity end portion 3310, first blade slot 3320, endportion 3330 and second blade slot 3340 previously shown in FIG. 34 havebeen omitted from FIG. 35.

Vacuum coupling 3380 is coupled to a vacuum supply line 3500. Vacuumsupply line 3500 provides a vacuum to vacuum chamber 3360. The vacuumcauses air to pass through access ports 3365, 3370, and 3375 into vacuumchamber 3360 (shown by arrows in FIG. 35) when access ports 3365, 3370,and 3375 are open to the atmosphere. When circularly shaped surface 3350of blade guide 3300 is placed in contact with the surface of sclera 102the vacuum in vacuum chamber 3360 causes sclera 102 to adhere to thesurface of circularly shaped surface 3350. The adhesion caused by thevacuum in vacuum chamber 3360 restrains the movement of sclera 102 whencurved cutting blade 1820 is rotated into sclera 102 to make anincision.

This alternate advantageous embodiment of the present invention requiresvacuum supply line 3500 be to connected to a vacuum supply (not shown).FIG. 36 shows how vacuum supply line 3500 is connected to vacuumcoupling 3380 of blade guide 3300. FIG. 37 shows how vacuum supply line3500 may be externally located along the length of surgical tool 1100.

FIG. 38 shows a flow chart of an advantageous embodiment of a method ofthe present invention for making incisions to form a scleral pocket 120for a scleral prosthesis 200. The steps of the method are generallydenoted with reference numeral 3800. Blade mount housing 1130 ofsurgical tool 1100 is positioned over sclera 102 of eye 100 by aligningexternal reference line 2140 of blade mount housing 1130 with limbus 106of eye 100 (step 3810). Then blade mount housing 1130 and blade 1140 areplaced into contact with sclera 102 (step 3820).

The movement of sclera 102 and surgical tool 1100 is then restrained byengaging and holding sclera 102 with scleral tissue fixation tool 3000(step 3830). Surgical tool 1100 rotates curved cutting blade 1820through sclera 102 to make an incision to form scleral pocket 120 (step3840). When the incision is complete surgical tool 110 rotates curvedcutting blade 1820 back out of the incision made through sclera 102(step 3850). Then sclera 102 is released by disengaging scleral tissuefixation tool 3000 (step 3860). The incision forms scleral pocket 120 toreceive scleral prosthesis 200.

FIG. 39 shows a flow chart of an alternate advantageous embodiment of amethod of the present invention for making incisions to form a scleralpocket 120 for a scleral prosthesis 200. The steps of the method aregenerally denoted with reference numeral 3900. Blade mount housing 1130of surgical tool 1100 is positioned over sclera 102 of eye 100 byaligning external reference line 2140 of blade mount housing 1130 withlimbus 106 of eye 100 (step 3910). Then blade mount housing 1130 andblade 1140 are placed into contact with sclera 102 (step 3920).

The movement of sclera 102 and surgical tool 1100 is then restrained byengaging and holding sclera 102 with a vacuum from vacuum chamber 3360of blade guide 33000 (step 3930). Surgical tool 1100 rotates curvedcutting blade 1820 through sclera 102 to make an incision to formscleral pocket 120 (step 3940). When the incision is complete surgicaltool 110 rotates curved cutting blade 1820 back out of the incision madethrough sclera 102 (step 3950). Then sclera 102 is released by ventingthe vacuum in vacuum chamber 3360 of blade guide 3300 (step 3960). Theincision forms scleral pocket 120 to receive scleral prosthesis 200.

FIG. 40 shows a first perspective view of an alternate advantageousembodiment of blade 1140 of surgical tool 1100 of the present inventioncomprising support arm 4010 and curved cutting blade 4020. In theembodiment of blade 1140 shown in FIGS. 18-20 support arm 1810 andcurved cutting blade 1820 are formed as a unitary structure. In theembodiment of blade 1140 shown in FIG. 40 curved cutting blade 4020 isdetachable from support arm 4010.

FIG. 41 shows a second perspective view of the alternate advantageousembodiment of blade 1140 shown in FIG. 40. Curved cutting blade 4020comprises an extension 4030 having portions that form an aperture 4040through extension 4030. As shown in FIG. 42, a string-like connector4200 (e.g., a plastic fiber 4200) may be used to tie a scleralprosthesis 200 to extension 4030. Surgical tool 1100 rotates support arm4010 and causes curved cutting blade 4020 to pass through sclera 102 aspreviously described.

However, in this advantageous embodiment of the invention curved cuttingblade 4020 is disconnected from support arm 4010 after the incision insclera 102 has been made. Curved cutting blade 4020 remains within theincision. Surgical tool 1100 is removed. Then the leading edge of curvedcutting blade 4020 is withdrawn from the incision in the forwarddirection. Because curved cutting blade 4020 is tied to scleralprosthesis 200 by string-like connector 4200 the withdrawal of curvedcutting blade 4020 from the incision pulls scleral prosthesis 200 intothe incision. Curved cutting blade 4020 acts as a needle pulling thestring-like connector 4200. Curved cutting blade 4020 is thenre-attached to support arm 4010 for use in making the next incision ofsclera 102.

FIG. 43 shows a first perspective view of a second alternateadvantageous embodiment of blade 1140 of surgical tool 1100 of thepresent invention comprising support arm 4310 and curved cutting blade4320. In the embodiment of blade 1140 shown in FIGS. 18-20 support arm1810 and curved cutting blade 1820 are formed as a unitary structure. Inthe embodiment of blade 1140 shown in FIG. 43 curved cutting blade 4320is detachable from support arm 4310.

In addition a central portion 4330 of curved cutting blade 4320 isdetachable from the other portions of curved cutting blade 4320. Curvedcutting blade 4320 comprises three portions. The three portions are (1)detachable central portion 4330, and (2) detachable tip 4340, and (3)blade portion 4350. FIG. 44 shows a second perspective view of thesecond alternate advantageous embodiment of blade 1140 shown in FIG. 43.Central portion 4330 is shown shaded in FIGS. 43 and 44.

Curved cutting blade 4320 is rotated into sclera 102 to form an incisionin the manner-previously described. The curved cutting blade 4320 isdetached from support arm 4310 while curved cutting blade 4320 remainswithin the incision. FIG. 45 shows a side view of the three portions(4330, 4340, 4350) of curved cutting blade 4320 within an incision.

Then detachable tip 4340 is detached from detachable central portion4330 (e.g., by forceps) and is removed from the incision. Then bladeportion 4350 is detached from detachable central portion 4330 and isremoved from the incision. Detachable central portion 4330 is leftwithin the incision to serve as a scleral prosthesis 200.

FIG. 46 shows a first perspective view of a third alternate advantageousembodiment of blade 1140 of surgical tool 1100 of the present inventioncomprising support arm 4610 and curved cutting blade 4620. In theembodiment of blade 1140 shown in FIGS. 18-20 support arm 1810 andcurved cutting blade 1820 are formed as a unitary structure. In theembodiment of blade 1140 shown in FIG. 46 curved cutting blade 4620 isdetachable from support arm 4610.

In addition curved cutting blade 4620 has portions that define a conduit4630 through curved cutting blade 4620. Slidably disposed within conduit4630 is scleral prosthesis 200. Plunger 4640 is also slidably disposedwithin conduit 4630. Plunger 4630 abuts scleral prosthesis 200. FIG. 47shows a second perspective view of the third alternate advantageousembodiment of blade 1140 shown in FIG. 46. Scleral prosthesis 200 isshown shaded in FIGS. 46 and 47.

Curved cutting blade 4620 is rotated into sclera 102 to form an incisionin the manner previously described. The curved cutting blade 4620 isdetached from support arm 4610 while curved cutting blade 4620 remainswithin the incision. FIG. 48 shows a cross sectional side view of curvedcutting blade 4620. Curved cutting blade 4620 is withdrawn from theincision. Plunger 4640 remains in place against scleral prosthesis 200as curved cutting blade 4620 is withdrawn from the incision. Plunger4640 prevents scleral prosthesis 200 from being withdrawn from theincision. Plunger 4640 finally pushes scleral prosthesis 200 out ofconduit 4630 and into the incision. Then plunger 4640 is withdrawn fromthe incision leaving scleral prosthesis 200 properly placed within theincision.

In one advantageous embodiment, scleral prosthesis 200 is capable ofbeing filled with a fluid. Scleral prosthesis 200 is filled with a fluidafter scleral prosthesis 200 has been placed within the incision inorder to increase the size of scleral prosthesis 200.

The invention having now been fully described, it should be understoodthat it may be embodied in other specific forms or variations withoutdeparting from its spirit or essential characteristics. Accordingly, theembodiments described above are to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than the foregoing description,and all changes which come within the meaning and range of equivalencyof the claims are intended to be embraced therein.

1. A surgical tool for making an incision in scleral tissue of an eyecomprising: a curved surgical blade operable under control of saidsurgical tool to rotate with respect to said surgical tool through saidscleral tissue of said eye to make an incision having the form of ascleral pocket that is capable of receiving a scleral prosthesis.
 2. Asurgical tool as claimed in claim 1 wherein said curved surgical bladehas dimensions that make an incision in said scleral tissue that isapproximately one and one half millimeters wide and approximately fourmillimeters long, said incision being located approximately four hundredmicrons under a surface of said scleral tissue.
 3. A surgical tool asclaimed in claim 1 further comprising a base housing comprising: a firstdrive shaft for providing bidirectional rotational motion to saidsurgical blade; a drive motor coupled to said first drive shaft, saiddrive motor capable of providing bidirectional rotational motion to saidfirst drive shaft; and a control cable receptacle coupled to said drivemotor, said control cable receptacle capable of receiving electricalpower from an external power source and providing said electrical powerto said drive motor to operate said drive motor.
 4. A surgical tool asclaimed in claim 1 further comprising a surgical tool controller,wherein said surgical tool is capable of receiving control signals fromsaid surgical tool controller and capable of using said control signalsto control said surgical blade of said surgical tool; and wherein saidsurgical tool controller is capable of sending said control signals tosaid surgical tool in response to receiving control signals from asurgeon who is using said surgical tool to make an incision in saidscleral tissue of said eye.
 5. A surgical tool controller as claimed inclaim 4 further comprising a foot switch coupled to said surgical toolcontroller through a control signal line, said foot switch capable ofsending control signals from said surgeon to said surgical toolcontroller to control said surgical blade of said surgical tool.
 6. Asurgical tool as claimed in claim 3 further comprising: a drive shafthousing coupled to said base housing, said drive shaft housingcomprising a second drive shaft coupled to said first drive shaft; ablade mount housing comprising a third drive shaft coupled to saidsecond drive shaft, said blade mount housing being mounted on said driveshaft housing at an angle with respect to a central axis of said driveshaft housing; and wherein said surgical blade is coupled to said thirddrive shaft of said blade mount housing.
 7. A surgical tool as claimedin claim 6 further comprising an external reference line marked on asurface of said blade mount housing, said external reference lineindicating a desired location for placing said surgical tool on an eyeto make an incision in scleral tissue of said eye to form a scleralpocket that is capable of receiving a scleral prosthesis.
 8. A surgicaltool as claimed in claim 7 wherein said external reference line islocated on said surface of said blade mount housing so that a desiredlocation on said eye for aligning said external reference line with saideye is a limbus of said eye.
 9. A surgical tool as claimed in claim 6wherein said surgical blade comprises: a rotatable support arm having afirst end coupled to said third drive shaft of said blade mount housing;and a curved cutting blade having a first end coupled to a second end ofsaid rotatable support arm, said curved cutting blade having a secondend that is capable of making an incision in said scleral tissue that isapproximately one and one half millimeters wide and approximately fourmillimeters long, said incision being located approximately four hundredmicrons under a surface of said scleral tissue. 10.-30. (canceled)
 31. Asurgical tool comprising: a curved surgical blade; and a motor operableto rotate said curved surgical blade with respect to said surgical toolto move said curved surgical blade through scleral tissue of an eye tomake an incision, said incision forming a scleral pocket in the regionof the ciliary body of said eye, said scleral pocket having a formcapable of receiving a scleral prosthesis to increase the effectiveworking distance of the ciliary muscle of said eye.
 32. The surgicaltool as set forth in claim 31 further comprising a first drive shaftassociated with said motor and operable to drive said rotation of saidsurgical blade.
 33. The surgical tool as set forth in claim 31 furthercomprising a receptacle associated with said motor that is capable ofreceiving electrical power from a power source.
 34. The surgical tool asset forth in claim 33 wherein said receptacle is further capable ofproviding said electrical power to said motor.
 35. The surgical tool asset forth in claim 31 further comprising a controller operable togenerate control signals.
 36. The surgical tool as set forth in claim 35wherein said controller is associated with said motor and said generatedcontrol signals control movement of said surgical blade.
 37. Thesurgical tool as set forth in claim 36 wherein one controlled movementof said surgical blade is to make said incision.
 38. The surgical toolas set forth in claim 36 wherein one controlled movement of saidsurgical blade is to position said surgical blade to make said incision.39. The surgical tool as set forth in claim 35 further comprising aswitch for use by a surgeon, said switch associated with said controllerand capable of receiving control signals from the surgeon, said receivedcontrol signals to control movement of said surgical blade.
 40. Thesurgical tool as set forth in claim 39 wherein one controlled movementof said surgical blade is to make said incision.
 41. The surgical toolas set forth in claim 39 wherein one controlled movement of saidsurgical blade is to position said surgical blade to make said incision.42. The surgical tool as set forth in claim 31 further comprising apower source.
 43. The surgical tool as set forth in claim 42 whereinsaid power source is externally coupled to said surgical tool.
 44. Asurgical tool comprising: a curved surgical blade; and a controlleroperable to control rotational movement of said curved surgical bladethrough scleral tissue of an eye to make an incision, said incisionforming a scleral pocket in the region of the ciliary body of said eye,said scleral pocket having a form capable of receiving a scleralprosthesis that increases the effective working distance of the ciliarymuscle of said eye.
 45. The surgical tool as set forth in claim 44further comprising a motor operable to receive control signals from saidcontroller, said control signals controlling movement of said surgicalblade.
 46. The surgical tool as set forth in claim 45 wherein onecontrolled movement of said surgical blade is to make said incision. 47.The surgical tool as set forth in claim 45 wherein one controlledmovement of said surgical blade is to position said surgical blade tomake said incision.
 48. The surgical tool as set forth in claim 44further comprising a first drive shaft associated with said controllerand operable to drive said movement of said surgical blade.
 49. Thesurgical tool as set forth in claim 44 further comprising a receptaclethat is capable of receiving electrical power from a power source. 50.The surgical tool as set forth in claim 49 wherein said receptacle isfurther capable of providing said electrical power to said controller.51. The surgical tool as set forth in claim 44 further comprising aswitch for use by a surgeon, said switch associated with said controllerand capable of receiving control signals from the surgeon, said receivedcontrol signals to control movement of said surgical blade.
 52. Thesurgical tool as set forth in claim 51 wherein one controlled movementof said surgical blade is to make said incision.
 53. The surgical toolas set forth in claim 51 wherein one controlled movement of saidsurgical blade is to position said surgical blade to make said incision.54. The surgical tool as set forth in claim 44 further comprising apower source.
 55. The surgical tool as set forth in claim 54 whereinsaid power source is externally coupled to said surgical tool.
 56. Asurgical tool comprising: a curved surgical blade; and an apparatusoperable to rotate said curved surgical blade through scleral tissue ofan eye to make an incision, said incision forming a scleral pocket inthe region of the ciliary body of said eye, said scleral pocket having aform capable of receiving a scleral prosthesis to increase the effectiveworking distance of the ciliary muscle of said eye.
 57. The surgicaltool as set forth in claim 56 further comprising a first drive shaftassociated with said apparatus and operable to drive said movement ofsaid surgical blade.
 58. The surgical tool as set forth in claim 56wherein said apparatus is a motor and said surgical tool furthercomprises a receptacle associated with said motor that is capable ofreceiving electrical power from a power source.
 59. The surgical tool asset forth in claim 58 wherein said receptacle is further capable ofproviding said electrical power to said apparatus.
 60. The surgical toolas set forth in claim 56 wherein said apparatus is a motor and saidsurgical tool further comprises a power source.
 61. The surgical tool asset forth in claim 60 wherein said power source is externally coupled tosaid surgical tool.
 62. The surgical tool of claim 1, wherein the curvedsurgical blade is operable, under the control of the surgical tool, torotate through the scleral tissue of the eye to make the incision, thesurgical blade being rotatable about a central axis of a blade mounthousing on which the surgical blade is mounted.
 63. The surgical tool ofclaim 1, wherein the curved surgical blade has an end that is operable,under the control of the surgical tool, to be rotated in one directioninto and then out of the scleral tissue of the eye to make the incision.64. The surgical tool of claim 1, wherein the curved surgical bladecomprises a cutting blade having an end operable to be moved through ananterior surface of the scleral tissue of the eye without passingthrough a posterior surface of the scleral tissue of the eye to make theincision.
 65. The surgical tool of claim 31, wherein the curved surgicalblade comprises a cutting blade having an end operable to be movedthrough an anterior surface of the scleral tissue of the eye withoutpassing through a posterior surface of the scleral tissue of the eye tomake the incision.
 66. The surgical tool of claim 44, wherein the curvedsurgical blade comprises a cutting blade having an end operable to bemoved through an anterior surface of the scleral tissue of the eyewithout passing through a posterior surface of the scleral tissue of theeye to make the incision.
 67. The surgical tool of claim 56, wherein thecurved surgical blade comprises a cutting blade having an end operableto be moved through an anterior surface of the scleral tissue of the eyewithout passing through a posterior surface of the scleral tissue of theeye to make the incision.